Tree squirrels, such as the Eastern Gray Squirrel (Sciurus carolinensis) and the Fox Squirrel (Sciurus niger), are overwhelmingly diurnal, meaning they are active during the day. Foraging is a behavior almost exclusively confined to daylight hours for these common species. The question of whether squirrels forage at night usually arises from misidentification or observation of specific environmental exceptions. Understanding their typical daytime pattern provides a clear answer to why nighttime foraging is not their standard practice.
The Squirrel’s Typical Daytime Schedule
The daily rhythm of a tree squirrel is closely tied to the cycle of the sun. Squirrels emerge from their nests, called dreys, shortly after sunrise to begin their activities. Their foraging behavior is characterized by a bimodal pattern throughout the warmer months, meaning they experience two distinct peaks of activity separated by a mid-day rest period.
The first and most intense foraging peak occurs in the early morning, typically within two hours after sunrise. This burst of activity focuses on finding and consuming food. A second peak begins in the late afternoon, usually two to five hours before sunset, when squirrels gather stores to be cached or consumed before retreating to their overnight shelter.
During the warmest part of the day, activity significantly decreases, allowing the squirrels to rest, groom, or remain in the cool of their drey or a tree cavity. In the winter, this bimodal pattern often shifts to a unimodal one, with a single, brief period of activity occurring around the warmest hours of midday. All major activities, including scouting for food and gathering seeds, are accomplished between dawn and dusk.
Biological Drivers of Diurnal Foraging
Tree squirrels do not forage at night due to their evolutionary adaptation to a daytime lifestyle. Their sensory biology and physiological needs are built for the light. Squirrels possess a retina dominated by cone cells, which are specialized for high visual acuity and color vision in bright light. This visual system is highly effective for detecting food sources, but it results in poor sight in low-light conditions.
Remaining active during the day also serves as an effective mechanism for predator avoidance. The squirrel’s primary predators at night, such as owls and raccoons, are naturally nocturnal. By retiring to a secure nest before dark, the squirrel minimizes overlap with these hunters, making daytime activity a safer strategy. Furthermore, tree squirrels have a relatively high metabolism, which is better suited for the warmer temperatures of the day. Being active at night would require excessive energy expenditure to maintain body temperature.
When Squirrels Are Active After Sunset
Reports of squirrels moving after sunset can often be traced to misidentification. The most common source of confusion is the presence of flying squirrels (Glaucomys species), which are genuinely nocturnal. Unlike common tree squirrels, flying squirrels have proportionally larger eyes and are active primarily after dark, gliding between trees to forage.
In rare instances, a common tree squirrel may briefly extend its activity into the twilight hours due to environmental pressures. Extreme hunger, a sudden disturbance to a nest, or the urgency of late-season caching might push an individual to forage slightly past the typical cessation of activity. This is not true nocturnal foraging and rarely extends deep into the night.
Artificial light in urban environments can also temporarily alter a squirrel’s schedule. Strong outdoor lighting, such as streetlights, can occasionally confuse a squirrel’s internal clock. Studies have shown that Eastern Fox Squirrels have extended their foraging activity by up to four hours after sunset in the presence of intense artificial lighting. This prolonged exposure can disrupt their natural behavior and is associated with an increased risk of predation.